From owner-freebsd-current@FreeBSD.ORG Sun Jan 1 21:18:04 2006 Return-Path: X-Original-To: current@freebsd.org Delivered-To: freebsd-current@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 0AB4E16A41F for ; Sun, 1 Jan 2006 21:18:04 +0000 (GMT) (envelope-from imp@bsdimp.com) Received: from harmony.bsdimp.com (vc4-2-0-87.dsl.netrack.net [199.45.160.85]) by mx1.FreeBSD.org (Postfix) with ESMTP id 52A4143D5A for ; Sun, 1 Jan 2006 21:18:03 +0000 (GMT) (envelope-from imp@bsdimp.com) Received: from localhost (localhost.village.org [127.0.0.1] (may be forged)) by harmony.bsdimp.com (8.13.3/8.13.3) with ESMTP id k01LHi4S097346; Sun, 1 Jan 2006 14:17:44 -0700 (MST) (envelope-from imp@bsdimp.com) Date: Sun, 01 Jan 2006 14:17:47 -0700 (MST) Message-Id: <20060101.141747.125947927.imp@bsdimp.com> To: PeterJeremy@optushome.com.au From: "M. Warner Losh" In-Reply-To: <20060101111945.GA42228@cirb503493.alcatel.com.au> References: <73774.1136109554@critter.freebsd.dk> <20060101111945.GA42228@cirb503493.alcatel.com.au> X-Mailer: Mew version 3.3 on Emacs 21.3 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-2.0 (harmony.bsdimp.com [127.0.0.1]); Sun, 01 Jan 2006 14:17:45 -0700 (MST) Cc: phk@phk.freebsd.dk, current@freebsd.org Subject: Re: FreeBSD handles leapsecond correctly X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 01 Jan 2006 21:18:04 -0000 In message: <20060101111945.GA42228@cirb503493.alcatel.com.au> Peter Jeremy writes: : On Sun, 2006-Jan-01 10:59:14 +0100, Poul-Henning Kamp wrote: : >http://phk.freebsd.dk/misc/leapsecond.txt : > : >Notice how CLOCK_REALTIME recycles the 1136073599 second. : : Thank you (and others) for your efforts in getting FreeBSD to this point. : : I did find what appears to be two hosts that both held the leap : indicator as "01", well after the leap second, until I unpeered them. That's OK. The 'ins' indicator is only used on June 30 and December 31. The leap second indicators will stay on as long as the up-stream servers have them turned on. Also, there's a 1024 second polling interval to consider, which can make the indicator persist for hours depending on the network topology, etc. : My firewall reset the leap indicator bit at 0030 UTC and the 5.4 host : reset it at about 0106 UTC. Neither the 6.0 nor 7.0 systems reset the : leap bit until I unpeered them at 0500 UTC. I suspect that both : systems saw the leap indicator bit in the NTP packets from each other : and held each other's leap indicator set. Once I unpeered them, both : reset their leap indicator bits. To be pedantic about what NTP does, it will keep the leap bit on so long as at least one of the peers with a lower stratum has its bit on. As I said above, it doesn't matter until June sometime. Yes, the June and December dates are hard wired into ntpd. The primary times are June 30 and December 31. The backup dates are March 31, September 30, but very few things implement those dates at all (more devices implement a more generic 'do leap second at the end of DOY #xxx). There won't be leap seconds on the alternative dates for at least tens of years (2030 to 2050 were the time frames that 2x year leap seconds won't be enough in projections that I've seen). Warner